view 52 KB version
|
| Flow cytometry can also be used to demonstrate
abnormalities in genetic material, but it cannot demonstrate which chromosomes are
involved. Here is a large aneuploid peak next to a diploid peak in a fetus with triploidy
(69, XXY). The large peak is due to the fact that the cell population from the fetus
contains three sets of chromosomes. The diploid peak comes from maternal cells (the tissue
sample used was placenta |
view 8 KB version
|
| Triploidy occurs when there is double fertilization of an
ovum (dispermy). The result may be 69, XXX or 69, XXY or 69, XYY. The extra set of
paternal chromosomes predisposes to formation of a partial mole, features of which may or
may not be grossly or microscopically apparent. |
view 22 KB version
|
| One characteristic feature of triploidy is syndactyly
involving the third and fourth digits of the fetal hand as shown here. |
